4- barrel VS IR injection

[bobcowan]

Originally Posted by Caprimaniac

Hmmm. Not really convinced yet.

Not really convinced of what?


Think of running Alpha-N, but might also try with MAP- sensor. If interconnected plumbing is needed (I wouldn't think so?), I suppose you use tubing to connect all 8 runners from somewhere below(?) the butterflies into a common box or whatever (and that's it?). That would be where the MAP sensor would go.

As I said, Wayne Presley sells a manifold that has the plenum built in. No mods needed. If you have a manifold that doesn't have the plenum built in, you can do just what you're thinking. it looks like this:


When it comes to cam, I would go with quite wide lobe separation, 110 +, but there will be quite some overlap- I would guess it wil have a RPM band to 7500 or 8000.
Yes, that really is the key. You can run just about any "size" cam you want, in regards to lift and duration. But the wider LSA really works well to prevent the reversion.
Inglese sells cams specifically for Webers. And Comp Cams (who now owns Inglese) makes Ford stroker cams with a wide LSA. I can tell you from experiance that those cams really do make a differance

The ECU will be of a newer model... Will run wasted spark with 2 x 4- towers and seqential injection.
Easy to do with off the shelf products. I'm considering updating my ECU to something similar. I'm also consider coil-on-plug systems, with a crank trigger.

I'm not sure about this: "Maximum power from a maximum build engine will come from a large 4 barrel TB. That big plenum underneath gives you a better fuel charge. " When I think of it, yes- OK- if you bulid a max Hp engine of a certain volume/stroke etc- let's say a a 800- 1500 Hp 347 drag engine, it might be so.
Well, I'm making somewhere around 630'ish hp - 510 on the chassis dyno. I'v discussed this with Gordon and Wayne both. To make more power, I would need to go with bigger heads. But, bigger heads won't match the IR system - tried that. For bigger heads and ports, I need a common plenum. Speaking from experiance, not theory. YMMV.

But let's take these facts into account:

Fullrace/ HO 4- cylinders run IR (for instance Cosworth roller barrel setups- 300 Hp and 2 litres 9000rpm?)

Throttle bodies are also popular with high output turbo- engines. (600Hp+ 4- cylinders.)

Should we assume no difference in throttle response and not very significant difference in Hp/Tq between a 4- barrel and IR?


Now I will look into crossram manifolds. Have seen them available from somewhere- athough I cannot remember where. (With a new manifold I could keep my Weber setup on a roadcar!)

Thanks for the input. Need more to be convinced!

Originally Posted by Caprimaniac

Found some interesting things at the GT40 forum Cross ram intakes - Page 2 - GT40s.com Good reading, some of it.

It also seems like Moon (and also Inglese, but only as a complete package) has a croosram manifold that supports DCOE carbs/ TB's.Mooneyes Online Store - Specialty Equipment Manufacturer, Speed and Custom Parts for Motorcycles and Automobiles

How would one of those work with 50mm TB's? Are the runners too small to support 600 Hp? The downside with this type of crossram is "how to get cold air into the throats"..? Two boxes and tubes from the front area is the sollution I can see...


Ok; let's have a look at those Aussie race- intakes.... Look great, work great- but the cost is 6000$ or so.

Remember the movie, "Corvette Summer"? Remember the hood?